Anti-Lead
Item: Choice Scarf
Ability: Clear Body
Nature: Jolly
EVs: 252 Atk / 252 Speed / 4 SpAtk
Moveset:
- Meteor Mash / Iron Head / Zen Headbutt
- Earthquake / Pursuit
- Thunder Punch / Ice Punch
- Grass Knot
Yep, this looks alot like standard ScarfMeta, but where's the boom boom (Explosion)? It isn't needed. As an anti-lead, this hunk of metal needs to stop common OU leads, with the ability to come in later in the battle and play revenge killer, as well.
Meteor Mash / Iron Head / Zen Headbutt: As on all other Metagross sets, is it's STAB of choice, but since it is an anti-lead, the accuracy might need to be upped to assure that whatever might need to be hit, is hit, which is why Iron Head is a suitable replacement on this set. Also, if you are worried about the potential Lead Machamp, Zen headbutt could also find it's way into the STAB move of choice section of this moveset.
Earthquake: The targets of this move should be obvious. Heatran, Infernape, Magnezone, and other Metagross. Most importantly though, Heatran and Infernape, since they are fairly common leads. It might still be advised to make the switch on Nape though, since it will most likely be holding Sash as a lead.
Thunder Punch / Ice Punch: Thunder Punch is listed to hit more for the revenge kills late game if Metagross can survive it's role as anti-lead, and come back later. With Stealth Rock damage, you should be able to OHKO Gyrados and Starnie, or put a hurt on Skarmory. Ice Punch is suggested for Dragonite and Flygon (especially D-nite, also becoming a popular anti-lead Poke).
Grass Knot: On a minus SpAtk nature? Has this Metagross malfunctioned? Nope! It's there to score the 2HKO on one thing...Swampert (as LeadPert). Since Swampert can absolutely wall the rest of this Metagross' set, it is a necessity. This can take your opponent by surprise, since they will suspect a switch while they think they are going to just freely set up rocks, but then Grass Knot happens. They still get their Rocks into place, but they will switch, since they are going to be plannng on using Pert later in their battle, thus giving you a free shot at something else.
Teammates: Anything with Heal Bell or Aromatheorpy is almost a must. If you want the Metagross to play revenge killer later in your battle, you don't need paralysis or burn slowing it down. Blissey, and Vaporeon can both preform this job nicely.
Other Options: A Hasty nature could be used in tandem with Hidden Power Fire to hit Skarmoy and Forretress harder, but you still will only be getting 2HKO at best, and those aren't even garenteed. If this option is taken though, it is suggested to use Hidden Power Fire in place of whatever elemental punch you would have been using.